Switch actuating mechanism



July 27, 1965 B. MUzzALL, JR 3,196,707

SWITCH ACTUATING MEGHANISM Filed Feb. 9, 1962 INVENTOR ,4s/f fuzz/m4,Je.

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United States Patent O 3,196,707 SWTJCH ACTUATNG h/lECl-ANlSll/l Lylelll. Muzzall, lr., Box 56, Mount Vernon, Wash. Filed Feb. 9, 1952, Ser.No. 172,319 Claims. (Cl. 7d- 522) This invention relates to anelectrical switch actuating mechanism, and more particularly to a heavyduty, weight responsive switching device with fully adjustable fulcrummeans so as to be of universal application.

Switch actuating mechanism according to the invention is essentiallycharacterized by a lever mechanism consisting of a lever arm supportedon a fully adjustable fulcrum assembly and biased at one end by a springloaded electric switch and supporting at the other end an actuatingWeight.

By way of typical example, one iield of use of such a switch actuatingmechanism is with respect to bulk feed receptacles such as poultry orcattle feeders, wherein one leg of the feed receptacle is placed on theoutboard end of the lever arm of the mechanism. As thus installed, thelevel of feed in the feed receptacle is maintained by the varying weightof the receptacle shutting od and turning on the switch, which in turncontrols the feed ilow to the receptacle. Regulation of the level offill of the receptacle is by adjustment of the fulcrum means and byadjustment of the point of placement of the receptacle weight on thelever arm. Of course, the invention is not limited to the control of thebulk feed of poultry or cattle but can be used to control bulk feedingof any liquid or granular solid for any purpose. The device will thus beunderstood to have utilitywhereever it is desirable to have an electricswitch actuated in response to change in weight.

An object of the present invention is to provide a weight responsiveswitching device having relatively few parts, which Iis rugged andcapable of response when subjected to heavy weight, and which is alsocapable of being adjusted to be responsive at any desired weight over awide range of weights.

Another object of this invention is to provide a switch of the abovedescribed character which can be manufactured solely from rolled stockmaterial which is readily available on the open market, thus eliminatingthe need of any special casting or manufacturing apparatus.

A further object of this invention is to provide a switch "\of the abovedescribed character which due to its construction is able to withstandan extremely heavy loading and at the same time can be built strongenough to provide a safety factor of several times any anticipated load.

A still further object of this invention is to provide a switch of theabove described character which is simple in construction, is durable inuse, is efcient in operation, and can be economically manufactured.

Yet another object and commercially important feature of the inventionis found in the slidably adjustable fulcrum arrangement characterizingthe mechanism, enabling the mechanism to be instantly adjustable to meetthe requirements of any particular use environment presented. i

More specifically, its fulcrum block or frame is simply and fullyadjustable by a sliding action, even with the mechanism installed andinluse, and the wide range of adjustment thereof enables quickadaptation of the mechanism to automatically control the material flowinto a receptacle such as a feed tank or trough, irrespective of whetherthe iilled receptacle is light or heavy. As a result of this capability,users such as farmers or industrial plants having only periodic need forsuch a switch actuating mechanism need have on hand only one size ofmechanism. Merchandising of such mechanism is also considerablysimplified in that the full flexibility of the lfi? Patented July 27,1965 mechanism for various usages eliminates any need for an inventoryof more than one size.

Other objects and advantages will be apparent from the followingdescription, appended claims and annexed drawing.

Referring to the drawing wherein like reference characters designatelike parts throughout the several views:

FIG. 1 is a perspective View of the device of this invention showing therelationship of its several parts.

FIG. 2 is a side elevation View of the invention, with various partsbroken away for clarity of illustration, illustrating the mechanism insupporting relation with respect to the leg of a bulk materialreceptacle.

FIG. 3 is an end elevation view, taken from the inboard end of themechanism.

FG. 4 is a sectional View taken substantially along line 4 4 of FIG. 2,and showing in detail the relationship of the lever arm to the fulcrumassembly and the base member.

Referring rst to FIG. 1 of the drawings, the mechanism of this inventioncomprises a housing 1t) having a base portion 12, side walls 14 and 16,and a top portion 18. The side walls 14, 15 and base portion 12 togetherdefine a generally U-shaped cross-section throughout a greater part ofthe length of the device, including the outboard end thereof. A topportion 18, the side walls 14, 16 and the base portion 12 together forma crosssection of box form at the inboard end of the device. Anadjustable, spring loaded electric switch mechanism Ztl, of conventionaltype per se, is secured tothe top portion 18 and is provided with aremovable cover t portion 22, a cover securing post 24, and a clampedconholes in both the plate 28 and top portion 1S, and are anchored inthe base of the switch mechanism 2.9 which lies in contact with theupper surface of the top portion 1S. An access hole (not shown) isprovided in the base portion of the housing beneath plate 28 forinserting the tip end of a screwdriver through when asemblying theswitch and housing. Plate 28 is provided with a post 32 having a centralbore through which a switch actuating member 341 projects. The Switchactuating member 34 is biased downwardly by resilient means in the formof an adjustable compression spring 36 (shown somewhat diagrammatically)located within the switch cover ZZ. ln the position shown the spring 36normally holds switch contact points (not shown) in a closed position,thus completing a iiow control circuit of which the switch is a part.The actuating member 34 rests at its lower end against the inboard end33 of a lever arm 4t).

The lever arm 4) is secured to the housing 19 by a locating rod 42 whichextends through holes 44 drilled through the side walls 14 and 16 of thehousing l@ and through the lever arm 49, being retained in position bysuitable means such as cotter pins 46.

The leverjarm it? rests on a slidably adjustable fulcrum eans 43comprising a fulcrum rod St) supported at the ends thereof by supportplates 52 which cradle the rod 5t) substantially above the level of baseportion 12, as best shown at FEGS. 3 and 4. The plates 52 are slidablysupported by the inner surface of said base portion 12, and nest snuglybetween the inner surfaces of side portions 14, 16 and the outwardlyfacing side surfaces 4-'f lever arm 4l?. As will be apparent, thefulcrum means 4.8 is positionable anywhere longitudinally of the housinglil and lever arm itl from an inboard point where the inboard ends ofplates 572 substantially contact locating rod d2, to an outboard pointalmost directly under the applied loading.

ln the example shown, loading is applied by a leg 5d of a tank,container or' other receptacle for the bulli material, which leg 54 canbe adjustable in length in a manner conventional per se, as by having athreaded foot 5o, and is placeable at any desired point to be in contactwith the upper surface of lever member dll. liengitudinal adjustment ofthe fulcrum means occurs, in relation to such leg Slt, simply by slidingthe same along the base portion l2 and lever member dll, as indicated bythe arrow designated 53 in FIG. 2. As evident, the solid line showing inFlG. 2 of the fulcrum means comprising rod 5t) and plates 52. is atypical setting thereof for actuation of the switch mechanism under arelatively light loading, while the dotted line showing of such rod andplates (as indicated at Sd and 5?!) illustrates a typicalsetting of thefulcrum means for switch actuation under relatively heavy loading.

ln consideringthe operation of the switch actuating.

mechanism illustrated, it will be understood that as illustrated in FIG.2, the'loading exerted by leg 57i is less than necessary to overcome thereaction force of spring 36 in the switch mechanism Ztl. However, as theweight being applied to lever arm lu by leg 55E is increased, theoutboard moment about fulcrum rod E@ is also increased and eventuallythe force of the inboard end of the lever arm itl pushing up against theactuating member overcomes theforce of the spring lo and causesactuation of the switch mechanism 2l).

When the switch mechanism 2li is used as a control for the feeding ofbulk poultry or cattle feed, for example, a leg of the receivingreceptacle, such as a feed tank or trough, is placed on the outboard endof the lever arm 49, as shown in FIG. 2. Bulk feed flows into thereceptacle through a suitable conduit or chute from a storage chamber.In a manner conventional per se, an electrically controlled olf-on valveor gate is located in the conduit and is also included in the electriccircuit with the switch mechanism 2li. in a typical circuit, theelectric switch mechanism 2d is normally closed and the feed controlvalve or gate normally in an open position, thus allowing feed to flowfrom the storage chamber into the feeding receptacle. When the feedreaches the desired level in the receptacle resting on the lever arm d,the combined weight of the receptacle and bulk material it containscauses lever arm lll to pivot, which in turn causes actuation of switchmechanism Ztl, closing the bulk feed valve or gate and cutting olf thesupply of feed to the receptacle. The bulk feed valve or gate thenremains in its closed position until gradual removal of feed from thereceptacle due to animals eating from it relieves the weight on leverarm ttl to the point where the force of spring 36 is no longer overcome.The switch mechanism 2lb is then restored to normal position, and bulkfeed ilow resumes. rl`hus, a desired level of feed in the receptacle isautomatically maintained by the varying weight of the receptacleshutting off and turning on the switch mechanism Ztl.

The relative lengths of the respective moment arms on each sif e of thefulcrum rod Sil determine the weight necessary to cause lever arm itl topivot and actuate the switch mechanism Ztl. As the adjustable fulcrumassembly 4S is moved to the right (as viewed in FIG. 2),V

a greater loading is required to produce the same switch actuating forcedue to the unbalancing of the moment arms to the left. Conversely, asmaller weight is required when the fulcrum means is moved to the left.ln this manner the switch actuating mechanism can be adjusted to make itresponsive to any loading over a wide range of receptacle weights.

alsof/o7 The holes in the side walls of the housing for locating rod l2are slightly enlarged so as to allow for the pivotal movement of thelever arm d@ and the diagonal movement of the locating rod t2 resultingfrom change of position of the fulcrum means 43.

A second manner of adjustment of the actuating mechanism is by varyingthe point of Contact of the load (ie. leg Se) with the lever arm dll.With the fulcrum means in a set position, movement of the loading pointto the left will make necessary the presence of a larger actuatingweight to overcome the force of spring 36. Fine adjustment can also beachieved by varying the compression of spring 36, as by means of nut oil(FlG, 2).

Due to the unique construction of the switch actuating mechanism of thisinvention there is good load distribution from the point of loading tothe base regardless of ethe position of fulcrum means. As best shown atFIG. 4, the actuating weight is transferred by the box construction oflever arm lll to the fulcrurn rod Sil along the full length of thelatter and is then evenly divided between the plates 52. of the fulcrummeans and is in turn transferred by the said plates along the lengththereof to areas of the base portion l2 which are contiguous to the sideportions lll 'and lo. This manner of load distribution provides for asturdy and stable installation, even when very heavy loading isinvolved.

The 'box form of construction shown permits use of relatively lightmetals, such as aluminum alloys, so that the mechanism can becomparatively light weight and rust resistant, and is relativelyinexpensive to ship in quantity.

The device is advantageously constructed wholly from rolled stockmaterial, thus making special manufacturing equipment unnecessary. Thehousing in its preferred form is constructed from two pieces cut fromrolled box stock. The first piece forms the base portion and a greaterpart of the side walls. It is cut so `as to form short side walls inthat portion of the housing having a U-Shaped cross-Section and higherside walls in that portion which takes on a boX shape. The top portionand the remaining portion of the side walls of the box shaped sectionare cut from the second piece with the side wall portions extendingdownward and in abutting engagement with the upwardly extending higherside walls of the first piece. The side wall portions are weldedtogether where they abut by conventional welding methods, and the jointis ground to form a smooth and continuous surface. The lever arm isconstructed from a short length of box stock of smaller cross-sectionfrom that used in the housing. The side walls of the fulcrum are madefrom flat rolled stock or can be cut from scraps from the material usedin the housing. The locating rod and support member portion of thefulcrum assembly are cut from small diameter rolled circular stock.

ln addition to the fabrication advantages, the use of rolled stockmaterial results in a strong and highly durable mechanism which is ableto withstand extremely heavy weights.

From the foregoing, further variations, modifications, adaptations andusages of switch actuating mechanism according to the invention will beapparent, within the scope of the following claims.

What is claimed is: y

ll. A weight responsive switch actuating mechanism comprising a basemember of elongated, channeled configuration, a switch actuating memberspaced above said base member, means mounting said switch actuatingmember on said base member, a rigid lever arm located within thechanneled area of said base member with one end of said arm contactingsaid switch actuating member, `and fulcrum means located within thechanneled area of said base member, said fulcrum means intermediatelysupporting said lever arm for pivotal movement thereof, said fulcrummeans being slidably adjustable along the channeled area of said basemember to vary the extent of lever arm loading necessary to actuate saidswitch actuating member. n

2. A switch actuating mechanism according to claim 1, wherein saidfulcrum means laterally spans said channeled area and comprises sideplates nested between said lbase member and said lever arm.

3. A weight responsive switch actuating mechanism comprising a housinghaving a rst portion of generally box shaped cross-section and a secondportion of generally U-shaped cross-section, said housing including abase member, side walls connected to and extending upwardly from saidbase member, and a top plate extending between said side walls a-t thebox-shaped end portion of the housing, switch means mounted on said topplate and including a spring loaded switch actuating member dependingbelow said top plate into said box shaped end portion, a lever armlocated in said extending substantially coextensively of said housingwith one end thereof contacting said switch actuating member, andslidably adjustable fulcrum means located in the generally U-shapedportion of said housing and intermediately supporting said lever arm forpivotal movement so that the end thereof engaging said switch memberactuates same when the other end thereof is downwardly loaded to adegree to overcome the spring loading of said switch member.

4. A switch actuating mechanism according to claim 3, wherein said leverarm includes side walls and said fulcrum means comprises laterallyspaced side plates and a fulcrum rod extending between said side plates,each said plate being slidably located between a side wall of said basemember and a side wall of said lever arm.

5. A switch actuating mechanism according to claim 4, wherein said sideplates each include a lower supporting edge that contacts said basemember so as to effectively distribute to the base member the loadingexerted on said fulcrum rod by the lever arm loading.

6. A switch actuating mechanism comprising: a housing having a baseportion, two side walls and a top porti-on, fulcrum means nestablysupported on said base portion between the side walls thereof, a rigidlever arm nestably supported on said fulcrum means for rotation aboutits point of contact with said fulcrum means, said lever arm havinginboard and outboard ends, an electric switch mechanism mounted on thetop portion of said housing and having a switch actua-ting member incontact with the inboard end of said lever means, resilient means urgingthe switch actuating member to a first position, and a load bearingsurface on the outboard end of said lever arm, whereby in response tothe presence of a predetermined load on the outboard end of the leverarm the lever arm pivots on the fulcrum means and causes the inboard endof the lever arm to overcome the force of said resilient means and movethe switch actuating means to a second position.

7. A switch actuating mechanism set forth in claim 6, wherein thefulcrum means comprises a pair of laterally spaced support plates and afulcrum rod interconnecting between said support plates, with said`support plates cradling the fulcrum rod substantially above the levelof said base portion, said support plates being supported on said baseportion between the side walls, and being slidable along said baseportion to adjust the lever arm moment.

8. A switch actuating mechanism as set forth in claim 7, wherein saidlever arm Vis characterized by a generally box shaped cross-section withthe side surfaces thereof spaced inwardly from the side walls of thehousing, and wherein said fulcrum means support plates nest snuglyIbetween the inner surfaces of said housing side walls and the outwardlyfacing side surfaces of said lever arm.

9. A switch actuating mechanism as set forth in claim 6, wherein saidresilient means comprises an adjustable compression spring.

10. A switch actuating mechanism as set forth in claim 6, wherein alocating rod extends through the side walls of the housing and throughthe lever arm at a point between the fulcrum means and the inboard endof the lever arm.

1l. A switch actuating mechanism as set forth in claim 10, wherein saidlocating rod extends through holes in the side walls of the housingwhich are substantially larger than said rod.

12. A switch actuating mechanism as set forth in claim 6, wherein saidhousing is of box form at its inboard end and channel form at itsoutboard end, and said lever arm is of smaller box form throughout.

13. A Weight responsive switch actuating mechanism comprising: anelongated base means; switch means including a switch actuating memberspaced above said base means; resilient means normally biasing theswitch actuating member toward the base means; mounting means for theswitch actuating member; means mounting said mounting means onto saidbase means; an elongated, rigid lever arm disposed above the base meansand having inboard and outboard ends, with the inboard end of said leverarm contacting said switch actuating member; and fulcrum means restingon said base means and intermediately supporting said lever arm forpivotal movement.

14. A weight responsive switch actuating mechanism comprising: anelongated base means; switch means including a switch actuating memberspaced above said base means; resilient means normally biasing theswitch actuating member toward the base means; mounting means for theswitch actuating member; means mounting said mounting means onto saidbase means; an elongated, rigid lever arm disposed above the base meansand having inboard and outboard ends, with the inboard end of said leverarm contacting said switch actuating member; and fulcrum means restingon said base member and intermediately supporting said lever arm forpivotal movement, said fulcrum means being slidably adjustable along thebase means to Vary the extent of lever arm loading and downwarddisplacement of the outboard end of the lever arm necessary to overcomethe force of the spring means and actuate said switch actuating member.

15. A switch actuating mechanism comprising: a housing having an inboardend portion and an outboard end portion, said housing comprising a fiat,generally rectangular base, flat side walls connected to and extendingupwardly from said base, said side walls being substantially higher atthe inboard end of the housing than throughout the remaining portion oftheir extent, a relat1vely flat top plate interconnecting between :theside walls at the inboard end of the housing, switch means mounted onsaid top plate and including a switch actuating member dependingtherefrom, through an opening in said top plate, and into the inboardend of said housing, spring means normally biasing said switch actuatingmember toward the base member, an elongated, rigid lever arm disposedabove the base and having inboard and outboard ends, with the inboardend of said lever arm contacting said switch actuating member; andfulcrum means rest- 1ng on s aid base between the side walls andintermediately supporting said lever arm for pivotal movement, a load'bearing surface on the outboard end of said lever arm, said fulcrummeans being slidably adjustable along the base to vary the amount oflever arm loading and the extent of downward displacement of theoutboard end of the lever arm to overcome the force of the spring meansand actuate said switch actuating member.

References Cited by the Examiner UNITED STATES PATENTS 2,119,567 6/38Williams 74-552X 2,602,350 7/52 Marcellus 79-522 BROUGHTON G. DURHAM,Primary Examiner.

1. A WEIGHT RESPONSIVE SWITCH ACTUATING MECHANISM COMPRISING A BASEMEMBER OF ELONGATED, CHANNELED CONFIGURATION A SWITCH ACTUATING MEMBERSPACED ABOVE SAID BASE MEMBER, MEANS MOUNTING SAID SWITCH ACTUATINGMEMBER ON SAID BASE MEMBER, A RIGID LEVER ARM LOCATED WITHIN THECHANNELED AREA OF SAID BASE MEMBER WITH ONE END OF SAID ARM CONTACTINGSAID SWITCHING ACTUATING MEMBER, AND FULCRUM MEANS LOCATED WITHIN THECHANNELED AREA OF SAID BASE MEMBER, SAID FULCRUM MEANS INTERMEDIATELYSUPPORTING SAID LEVER ARM FOR PIVOTAL MOVEMENT THEREOF, SAID FULCRUMMEANS BEING SLIDABLY ADJUSTABLE ALONG THE CHANNELED AREA OF SAID BASEMEMBER TO VARY THE EXTENT OF SAID LEVER ARM LOADING NECESSARY TO ACTUATESAID SWITCH ACTUATING MEMBER.